What is Hirschsprung's disease?

Hirschsprung* disease (HD) is a disease of the large intestine that causes severe
constipation or intestinal obstruction. Constipation means stool moves through the intestines slower than usual. Bowel movements occur less often than normal and stools are difficult to pass. Some children with
Hirschsprung disease can't pass stool at all, which can result in the complete blockage of the intestines, a condition called intestinal obstruction. People with
Hirschsprung disease are born with it and are usually diagnosed when they are infants. Less severe cases are sometimes diagnosed when a child is older. An
Hirschsprung disease diagnosis in an adult is rare.

What are the large intestine, colon, rectum, and anus?

The large intestine, which includes the colon and rectum, is the last part of the digestive tract. The large intestine's main job is to absorb water and hold stool. The rectum connects the colon to the anus. Stool passes out of the body through the anus. At birth, the large intestine is about 2 feet long. An adult's large intestine is about 5 feet long.

Why does Hirschsprung's disease cause constipation?

People with Hirschsprung disease have constipation because they lack nerve cells in a part or all of the large intestine. The nerve cells signal muscles in the large intestine to push stool toward the anus. Without a signal to push stool along, stool will remain in the large intestine.

In a healthy large intestine the nerve cells are found throughout the large intestine.

Short-segment Hirschsprung disease. Nerve cells are missing from the last segment of the large intestine.

Long-segment Hirschsprung disease. Nerve cells are missing from most or all of the large intestine and sometimes the last part of the small intestine.

How severe Hirschsprung disease is depends on how much of the large intestine is affected. Short-segment
Hirschsprung disease means only the last part of the large intestine lacks nerve cells. Long-segment
Hirschsprung disease means most or all of the large intestine, and sometimes the last part of the small intestine, lacks nerve cells.

In a person with Hirschsprung disease, stool moves through the large intestine until it reaches the part lacking nerve cells. At that point, the stool moves slowly or stops, causing an intestinal obstruction.

What causes Hirschsprung's disease?

Before birth, a child's nerve cells normally grow along the intestines in the direction of the anus. With
Hirschsprung disease, the nerve cells stop growing too soon. Why the nerve cells stop growing is unclear. Some
Hirschsprung disease is inherited, meaning it is passed from parent to child through
genes. Hirschsprung disease is not caused by anything a mother did while pregnant.

Hirschsprung Disease Definition

Hirschsprung disease: A congenital abnormality (birth defect) of the bowel in which there is absence of the ganglia (nerves) in the wall of the bowel. Nerves are missing starting at the anus and extending a variable distance up the bowel. This results in megacolon (massive enlargement of the bowel) above the point where the nerves are missing. (The nerves are needed to assist in the natural movement of the muscles in the lining of our bowels which move bowel contents through.)

Hirschsprung disease is an important condition. It is the commonest cause of lower intestinal blockage (obstruction) in the newborn period and later in infancy and childhood, Hirschsprung disease is a cause of chronic constipation.

The most common symptoms of the disorder are vomiting, constipation, distention (swelling) of the abdomen, and intestinal obstruction. There is a male predominance of about 4 to 1 in Hirschsprung disease -- 4 boys to each girl.

Hirschsprung disease can be caused by dominant mutations in the RET oncogene and by recessive mutations in a gene called the endothelin receptor type B gene on 13q22.

There are a number of disorders in which Hirschsprung disease is a feature. They include Down syndrome), Waardenburg syndrome, cartilage-hair hypoplasia, the Smith-Lemli-Opitz syndrome (type II) and primary central hypoventilation syndrome (known as Ondine's curse).